Multi-touch surfaces have become common in public settings, with large displays appearing in hotel lobbies, shopping malls and other high foot traffic areas. These systems are able to dynamically change their interface allowing multiple users to interact at the same time and with very little instruction.
There are situations when receiving haptic feedback before touching the surface would be beneficial. These include when vision of the display is restricted, such as while driving, and when the user doesn't want to touch the device, such as when their hands are dirty. Providing feedback above the surface would also allow for an additional information channel alongside the visual.
A mid-air haptic feedback system creates tactile sensations in the air. One way to create mid-air haptic feedback is using ultrasound. A phased array of ultrasonic transducers is used to exert an acoustic radiation force on a target. This continuous distribution of sound energy, which will be referred to herein as an “acoustic field”, is useful for a range of applications, including haptic feedback.
Accordingly, a system that provides various improved perceptions techniques for haptic feedback above interactive surfaces and requires no contact with either tools, attachments or the surface itself is desirable.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The apparatus and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.